1. Field
The disclosed embodiments relate to an improved rifle and its law enforcement and commercial variances and, more particularly, to an improved military rifle having modular subassemblies.
2. Brief Description of Earlier Developments
There are conventional firearms with an integral upper receiver and hand guard. The conventional firearms have a removable hand guard section fastened to the hand guard on the upper receiver with screws or other similar fasteners. Field removal/reinstallation of the conventional hand guard section hence involves removal/installation tools (for example screw drivers), and once removed the mounting screws may be lost. This is not desirable in operational conditions. Further, conventional firearms with an upper receiver having an integral hand guard, may encumber field removal and replacement of the barrel. By way of example, in a conventional military rifle, for example an “M-4”™ rifle available from Colt Defense having an upper receiver with integral hand guard, the barrel nut (fastening the barrel to the receiver) may be covered or “buried” within the hand guard thereby limiting accessibility to the barrel nut. Moreover, conventional barrel nuts may have features such as peripheral clearance slots, for the gas tube or operating rod of an indirect gas operating system, that further impair accessibility to surface or features of the barrel nut engaged in order to apply tightening or untightening torque to the barrel nut. As may be realized, rotation of the conventional barrel nut, such as at removal/replacement of the barrel, may involve additional undesired disassembly of the firearm systems. By way of example, the gas tube, or operating rod of an indirect gas operating system may have to be removed from the firearm in order to allow rotation of the barrel nut for nut removal. In other words, the operating rod or gas tube may have to be removed prior to barrel removal. Similarly, on reinstallation, the barrel and at least the operating rod of the firearm indirect gas operating system, or the gas tube may have to be assembled/connected to the receiver in sequence, rather than in unison, in order to allow rotation of the barrel nut. This is not desired. Further still, the interface between the barrel, receiver and barrel nut in conventional firearms may result in the barrel being eccentrically positioned in an uncontrolled manner relative to the mating bore of the receiver. This also is undesired. The exemplary embodiments disclosed herein overcome the problems conventional firearms as will be described further below.